.red-background-modal {
    max-width: 500px;
}

.red-background-container {
    padding: 0 15px;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.red-background-title {
    margin: 0 0 16px 0;
    text-align: center;
}

.red-background-preview {
    width: 350px;
    aspect-ratio: 3/4;
    border: 1px solid var(--background-modifier-border);
    margin: 0 auto 16px;
    overflow: hidden;
    position: relative;
    border-radius: 4px;
}

.red-background-preview-image {
    width: 100%;
    height: 100%;
    cursor: move;
    background-position: center;
    background-repeat: no-repeat;
    background-size: contain;
}

.red-background-preview-image.dragging {
    cursor: grabbing;
}

.red-background-controls {
    width: 100%;
}

.red-background-controls .slider {
    width: 200px; /* 将滑块宽度增加到300px */
}

/* 内置背景选择区样式 */
.red-background-builtins {
    display: flex;
    gap: 12px;
    margin-bottom: 18px;
    justify-content: center;
    flex-wrap: wrap;
}

.red-bg-thumb {
    width: 46px;
    aspect-ratio: 3/4;
    object-fit: cover;
    border-radius: 6px;
    border: 2px solid var(--background-modifier-border);
    box-shadow: 0 2px 8px rgba(80,180,255,0.08);
    cursor: pointer;
    transition: border-color 0.2s, box-shadow 0.2s;
    background: #f6f8fa;
}

.red-bg-thumb:hover {
    border-color: var(--text-accent);
    box-shadow: 0 4px 16px rgba(80,180,255,0.18);
}

.red-bg-thumb.selected {
    border-color: var(--text-accent);
    box-shadow: 0 0 0 2px var(--text-accent);
}